Projectile



Sept. 29, 1936. K. HAYDEN PROJEGTILE Filed Feb. 8, 1934 INVENTOR M ar/ WITNESSES 7 a. #L'W Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE 10 Claims.

This invention relates to projectiles used for ordnance purposes, and more particularly to projectiles used in large caliber guns for coast defense purposes, naval armament, and for miscellaneous artillery prfivided with either fixed or mobile positions.

In projectiles of the conventional type commonly used in modern guns of large calibers, the rearmost portion or base of the projectile forms a circular plane of the caliber required, positioned at right angles to the axis of the gun barrel, permitting the most effective area for receiving the maximum pressure of powder gases generated upon discharge of the gun concerned. This base of the conventional projectile although efiicient for receiving the powder thrust from its gun upon discharge thereof, becomes extremely ineflicient upon moving through air at high velocities, as the drag resistance or turbulent region created by the base of this form of projectile along its trajectory becomes a large percentage of the total air resistance encountered by the projectile in flight, substantially reducing the initial velocity received by the projectile upon discharge thereof.

The principal object of the invention is to devise a projectile for use in conventional ordnance retaining the advantages of the base construction used in conventional projectiles, for efficiently receiving the full effect of the explosive discharge I from its gun, and in addition, to provide a means for transferring the force of explosive discharge thus received, to an aerodynamically efficient projectile, so shaped as to reduce the drag resistance or turbulent region created behind such a projectile to a practical minimum, upon discharge thereof into air at high velocities.

Another object of the invention is to provide aerodynamically streamlined projectiles for ordnance purposes, and to provide a means for rotating these streamlined projectiles about their longitudinal. axes, upon discharge into air.

Another object of the invention is to straighten the trajectory of ordnance projectiles, and to increase the effective range of ordance projectiles thereby.

Another object of the invention is to reduce the loss of velocity by air resistance, of a projectile along its trajectory.

Other objects of the invention are to provide projectiles for ordnance purposes offering less frictional resistance to their gun barrels upon discharge therefrom,- than present conventional projectiles.

Still other objects of the invention are to increase the accuracy of fire of ordnance projectiles along their trajectory, by increasing the distance between the foremost point of contact and the rearmost point of contact of a projectile with its un barrel.

Additional objects of the invention will appear in the following specification, in which the preferred forms of the invention are described.

In the drawing similar reference characters refer to similar parts in all of the views of which,

Figure l is a side elevation of the improved projectile together with its carrier, hereinafter referred to as a duplex projectile, which is the subject matter of this application.

Figure 2 is an end elevation, taken at the front end of the rear portion of the duplex projectile, hereinafter referred to as the projectile carrier.

Figure 3 is a cross sectional view, taken through the duplex projectile on the line S3S3 illustrated in Figure 4.

Figure 4 is a longitudinal sectional view, taken on the axis of the duplex projectile, illustrating the relationship of the projectile and its carrier.

Figure 5 is a longitudinal sectional view, taken on the axis of the duplex projectile, illustrating a modified form of the invention.

Figure 6 is a cross sectional view, taken through the modified form of duplex projectile illustrated in Figure 5 on the line S6SG.

Figure 7 is a side elevation of the modified form of duplex projectile carrier illustrated in Figure 5, detached from its projectile body, and

Figure 8 is a side elevation of the detached modifid form of duplex projectile body.

Figure 9 is a side elevation of an alternate modified form of duplex projectile.

Figure 10 is an end elevation illustrating the rear end of the projectile carrier for the alternate modified form of duplex projectile illustrated in Figure 9.

Figure 11 is a cross sectional view, taken through the alternate modified form of duplex projectile illustrated in Figure 9, on the line Sit-SH of Figure 12.

Figure 12 is a longitudinal sectional view, taken on the axis of the alternate modified form of duplex projectile at right angles to the view illustrated in Figure 9, illustrating the relationship of the projectile and its carrier.

By referring to the drawing, it will be seen that the duplex projectile comprises a body portion I with the detonator head 2 threadably secured thereto, and is provided with a conoidal shaped front portion, hereinafter referred to as the nose of approximately one caliber in length, (distance A, Fig. 1) tapering to a front apex from a straight cylindrical central portion of the caliber required and approximately threequarters of a caliber in length (distance 3", Fig. 1) hereinafter referred to as the waist", with a portion tapering rearward from the wais of the projectile for a length of approximately three calibers (distance E, Fig. 8) to a rear apex, forming a conoidal shaped rear portion, hereinafter referred to as the tail. The projectile body I is provided with, the powder chamber 4, for receiving the projectiles powder charge, and the detonator head 2 may be provided with any of various time or impact fuses, such as are used in conventional projectiles, for detonating this powder charge. The tail of the projectile body I is also provided with the projecting splines 3 foriengaging the splined keyways 8 of the projectiles carrier 5. The projectile carrier has a straight cylindrical shape of approximately one and one-half calibers in length, and is provided with the conventional rotation band 5, inserted thereon for engaging the rifling of the conventional gun, and has its forward or projectile body end provided with a bevelled face and the conoidal shaped cavity I, with the keyways 8 splined therein, for receiving the tail portion of the projectile body I as illustrated in. Figure 1 and Figure 4.

By referringto Figure 1 in the drawing, a comparison may be made of the cylindrical area of a conventional projectile contacting its gun barrel, with the cylindrical areas of a duplex projectile contacting its gun barrel, in that conventional projectiles of three to four calibers in length, using the flat base and conoidal shaped nose construction average a cylindrical area contacting the sides of a gun barrel of approximately 65% to 70% of their cylindrical area. In Figure 1 of the drawing it will be seen that the distance B and the distance D are the only cylindrical areas of the duplex projectile contacting the bore of a gun barrel, the cylindrical areas A and "C" due to their diameters diminishing from the waist "B prevent frictional contact of-these areas with the bore of the gun barrel, where the lines R-'-R represent the surface of the rifling grooves and the lines LL represent the surface of the rifle lands, showing the enagement of the rotation band 6 with the rifle lands. The sum of these cylindrical areas "3 and -D" in contact with the gun barrel average approximately 40% to 45% of the cylindrical area of the duplex projectile, although this type projectile is approximately five calibers in length,

and in comparison with a conventional projectile of four calibers length of the same caliber, the sum of the cylindrical, areas B and D contacting the gun barrel are to less in area than the contacting cylindrical area of the conventional projectile. This reduction in the contactingcylindrical area of the duplex projectile over that of a conventional projectile of equal caliber, effects a material saving in the frictional resistance of the duplex projectile with the bore of its gun barrel upon discharge therefrom, e1- fecting a reduction in the wear of the gun barrel, and prolonging its useful life thereby.

Figure 2 illustrates the forward end oi the projectile carrier 5 with its projectile body removed to show the rotating band li projecting beyond the wall of the body I for the purpose ofengaging the rifling or a gun barrel and thereby impart rotation to the projectfle carrier 5, and illustrates the conoidal shaped cavity I with the recessed keyways 8 spline-d therein, for receiving the tail portion of the projectile body I.

The cross sectional view shown in Figure 3, taken on the line 83-83 of Figure 4, illustrates the projecting splines 3 of the projectile body I positioned on the tail portion thereof for engaging the recessed keyways 8 of the projectile carrier 5, and,

Figure 4 illustrates in longitudinal sectional view the assembly of the duplex projectile, showing the relative position of the projectile body I with its powder chamber 4 contained therein, for receiving the projectiles powder charge, upon removal of the detonator head 2, and with the projectile carrier 5 provided with the rotating band 6 inserted thereon, positioned on the tail portion of the projectile body I for engagement of the recessed keyways 8 of the carrier 5 with the splines 3 of the projectile body I. The engagement of the recessed keyways 8 on the carrier 5 with the splines 3 on the projectile body I is for the purpose of securing the projectile body I against rotation with its carrier 5, so that the rotational movement imparted to the projectile carrier 5 by the engagement of its rotating band 6 with the rifling of its gun barrel, upon discharge therefrom, will likewise impart rotation to its projectile body I.

The form of the invention illustrated in Figures 1, 2, 3, and 4 anticipates use in rifled guns of large calibers, where the conventional loading procedure requires placing the conventional projectile in the powder chamber of its gun barrel and force the projectile forward into position in the shot chamber, until the rotation band of the projectile engages the slopes of the lands in the un barrel, and inserting thereafter a powder charge in the powder chamber for discharging the projectile upon detonation of the powder charge. The weight of duplex projectiles of large calibers in this class of ordnance are sufficiently heavy to permit placing the body of the projectile in the powder chamber of a gun, inserting the projectile carrier 5 on the "tail portion thereof, and force the complete assembly forward into the gun's shot chamber to the required position for the carrier rotation band 5 to engage the slopes of the rifling similar to conventional pracof the duplex projectile body offers sufiicient frictional resistance to the gun barrel to secure tight frictional contact of the carrier cavity I with the tail portion of the projectile body I, permitting full engagement of the splines 3 on the body I with the keyways 8 on the carrier 5. Upon detonation of the guns powder charge, the projectile carrier 5, receiving the full efiective pressure of powder gases generated in the powder chamber, is discharged from the gun, carrying therewith its projectile body, and, rotating about its longitudinal axis by reason of the engagement of its rotation band 6 with the rifling of the gun barrel, also rotates its projectile body about the longitudinal axis thereof, due to the engagement of the splines 3 with the splined keyways 8.

The discharge of the duplex projectile creates a phenomenon peculiarly characteristic to this type projectile, in that the projectile body I-2 and the projectile carrier 5 separate along the initial trajectory generated," creating a new and shorter trajectory for the projectile carrier 5; and a continuation of the initial trajectory for the projectile body I-Z. The initial velocity received by the duplex projectile upon discharge into air, is constantly being retarded along its trajectory by the reacting areodynamic drag resistance created behind its projectile carrier 5, similar in eifect to that of conventional projec tiles, causing the rearmost or carrierportion 5 thereof, to increasingly lose the initial velocity received upon discharge from a gun barrel, but the projectile body l2 having only frictional connection of negligible resistance to its carrier 5, is not affected by the aerodynamic drag resistanoe're'acting on the carrier 5 and continues along the initial trajectory, causing a separation of its body l--2 with the carrier 5, this separation of the projectile body I--2 from the carrier 5 being accelerated by a positive air pressure exerted on the bevelled front face of the carrier 5 caused by the air flow'about the projectile body l-2. Inconsequenceof the separation between the carrier 5 and its projectile body l-2, the carrier cavity I will receive additional positive air pressure due to impact with the air, to further retard the velocity of the carrier 5. The ineflicient shape of the-carrier 5 from an aerodynamic viewpoint oifers a maximum of both impact resistance and drag'resistance to air, and generates another shorter trajectory than its projectile body thereby.

On the other hahd the projectile body l--2 due to its efficiently shaped aerodynamic form permits the flow of air about its body to resume a normal condition after passage thereof, creating a minimum of drag resistance or turbulency thereby, and materially reducing the total amount of air resistance reacting on the velocity of the projectile body l-2 along its trajectory, in turn materially straightening that trajectory and increasing the eifective range of the projectile thereby.

The views shown in Figures 5, 6, 7, and 8 illustrate a modified form of the invention anticipating use in guns of smaller caliber than that of the form illustrated in Figures 1, 2, 3, and 4, where the weight of the projectile body is not sufficient to insure a tight frictional contact with its carrier, requiring a means to secure the positive attachment of the projectile assembly until discharged from its gun barrel, but permitting separation of the projectile assembly after discharge thereof, and illustrates the modified projectile body I with the detonator head 2 threadably secured thereto, with the conoidal shaped front portion or nose, the cylindrical central portion or waist, and the conoidal shaped rear portion or tail including the splines 3 positioned thereon, and the projectile powder chamber 4 inclosed therein, similar in form and construction to the duplex projectile illustrated in Figures 1, 2, 3, and 4, with the exception that the tail portion of the modified projectile body I is provided with the bevelled groove 9 circumferentially incised thereon. The modified carrier 5 however, provided with the conventional rotation band 6 positioned thereon for engaging the rifling of the conventional gun barrel, and with its forward or projectile body end provided with the bevelled face and the conoidal shaped cavity 1 including the keyways 8 splined therein for receiving the tail of the projectile body, I with its splines 3 thereon, similar in form to the duplex projectile illustrated in Figures 1, 2, 3, and 4, has in addition thereto, provided the carrier cavity I with the locking arm chamber l3 circumferentially incised therein, containing the locking arms 10 chamfered on their rearward sides, each arm secured at one end by the looking arm pins H, so arranged as to permit limited centrifugal movement of the locking arms l0, and the expanding spiral springs l2 disposed at the unsecured ends of the locking arms In with their outward ends recessed into the looking arm chamber ll so as to press inwardly on the locking arms l thereby, as illustrated in Figure 6 of the drawing.

Upon assembly of the modified duplex projectile the "tail" portion of the body i entering the conoidal cavity 1 engages its splines 3 with the keyways 8 of the carrier moving outwardly the locking arms l0 on the carrier 5 and compressing the expanding locking arm spiral springs 12 thereby, until the tail" portion of the body I seats in the cavity I of the carrier 5 bringing into alignment the bevelled groove 9 on the body i with the locking arm chamber 13, innthe carrier 5 permitting the chamfered rearward face of the locking arms l0 to move inwardly and engage with the bevelled groove 9 of the body i by reason of the expansion of the locking arm Springs 12 on the carrier 5 insuring positive attachment of the projectile body I 2 with the projectile carrier 5 Upon discharge of the modified duplex projectile from its gun barrel, the rotation band 6 of the carrier 5 engaging the rifling of the gun barrel, rotates the carrier 5 and likewise imparts rotation to the projectile body l 2 due to the engagement of the splines 3 thereon with the keyways 8 in the cavity 1 of the carrier 5 as heretofore described. The centrifugal force generated by the carrier 5 due to the rotational movement imparted thereto in turn forces the locking arms Illoutwardly against the back of the locking arm chamber l3, disengaging the locking arms ID on the carrier 5 from the bevelled groove 9 on the projectile body I, permitting separation thereof with the projectile carrier 5 upon origination of the aerodynamic forces effecting the separation of the projectile body "-2 and its carrier 5 as heretofore described in the initial form of the invention illustrated in Figures 1, 2, 3, and 4.

It is to be seen that the modified form of duplexprojectile assembly illustrated in longitudinal sectional view in Figure 5, secures positive attachment of the carrier 5 to the body i by the engagement of the chamfered rearward face of the locking arms III in the locking arm chamber H of the carrier 5 with the bevelled groove 9 of the body 1 by reason of the inwardly expanding spiral springs l2 recessed into the locking arm chamber i3 and pressing against the unsecured ends of the locking arms ill to move inwardly the locking arms ill for engagement with the bevelled groove 9 of the body I thereby.

In Figure 6 a cross sectional view taken at right angles to the view shown in Figure 5 on the line 88-86 thereof, illustrates the projection of the rotation band 6 on the carrier 5 and shows the locking arm chamber i3 containing its locking arms I 0, each secured at one end by the locking arm pins H and so arranged as to permit limited outward movement thereof, also illustrating the spiral springs 12 disposed at the unsecured ends of the arms i0 and recessed into the locking arm chamber ii to force inwardly the locking arms l0 thereby, also showing the projectile body I with its splines 3 engaging the keyways 8 of the carrier 5 It may be seen that the centrifugal force exerted on the locking arms ID by the car-.

rier 5 upon rotation thereof, will force the locking arms In outwardly against the back of the locking arm chamber I3, effecting disengagement thereof with the bevelled groove 9 on the body l and permitting separation of the body "-2 from its projectile carrier 5 as previously described.

In Figure 7 a side view of the modified carrier 5 is illustrated, showing the external appearance of the carrier 5 with its rotation band 6 inserted thereon, and having the bevelled front face with the conoidal cavity I provided thererier 5 Figure 8 also illustrates graphically the general proportions of the projectile body in the various forms of the invention described heretofore and hereinafter, comprising the nose (A), the waist (B), and the tail (E).

Figure 7 and Figure 8 taken together represent graphically the separation of the duplex projectile body from its carrier illustrating the eflicient aerodynamic shape of the projectile body, and the inefllcient aerodynamic shape of the projectile carrier.

It will be seen that the contacting cylindrical areas of the modified duplex projectile illustrated in Figure 5, are identical with the contacting cylindrical areas in the initial form of the invention illustrated in Figure 1 and heretofore described, and will likewise effect equivalent saving in frictional resistance with its gun barrel, as the initial form of the invention previously described.

An alternate modified form of the invention is illustrated in Figures 9, 10, 11, and 12 anticipating use in guns of smaller caliber than that of the form illustrated in Figures 1, 2, 3, and 4, where the weight of the projectile body is not sufficient to insure a tight frictional contact with its carrier, requiring a means to secure the positive attachment of the projectile assembly until discharged from its gun barrel, but permitting separation of the projectile assembly after discharge thereof, and more particularly anticipates use in rifled guns requiring cartridges which use a cartridge case containing a powder charge with the projectile secured to the muzzle end thereof, to make a complete charge for the gun, and likewise anticipates use in small arms requiring cartridges. By referring to Figures 9, 10, 11, and 12, it will be seen that the alternate modified duplex projectile comprises a body portion I with the detonator head 2 threadably secured thereto, and has the conoidal shaped front portion or nose, the cylindrical central portion or "waist, and the conoidal shaped rear portion or tail with the splines 3 positioned thereon, and the powder chamber 4 inclosed therein, similar in form and construction to the duplex projectile illustrated in Figures 1,- 2, 3, and 4, with the exception that the projecting splines 3 nthe tail portion of the body I terminate at a further distance from the rear apex of the projectile body I, than do the splines 3 of either the initial form of the invention, or the modified form illustrated in Figures 1, 4, 5, and 8. The tail portion of the body I in addition thereto, is provided with the square aperture 14 having a, tapered rearward wall therein, and is positioned at right angles to the longitudinal axis of the projectile body I. The alternate modified carrier 5 however, provided with the conventional rotation band 6 positioned thereon, has its projectile body end provided with the bevelled face and the conoidal shaped orifice with' the keyways 8 splined therein, for receiving the tail portion of the projectile body I. It will be seen that the projectile carrier 5 is materially shortened in length over that of the initial form, or the modified form of projectile carrier illustrated in Figures 1, 4, 5, and 7 and is so arranged as to permit the tail portion of the projectile body I to extend through the conoidal shaped orifice I so that the aperture M of the body I is positioned in partial alignment with the base or rearward face of the carrier 5 permitting insertion of the lock pin l5 therein so as to draw the projectile body I into full engagement with its carrier 5 by the wedging action of the lock pin IS with the base of the carrier '5 and the aperture This lock pin (5 Mof the projectile body i preferably composed of the metal magnesium, and of a rectangular cross sectional shape, is tapered to fit the tapered aperture M of the projectile body i and is arranged to project each side of the aperture I 4, as shown in Figure 10, upon forcing the lock pin l5 into a driving fit with said aperture l4 and the rearward face-or base of the carrier 5 as shown in Figure 12, whereupon the entering end of the lock pin l5 may be bent rearwardly as shown in Figure 12, to secure positive attachment of the projectile body I and its carrier i Upon discharge of the alternate modified duplex projectile from its gun barrel, the rotation band 6 of the carrier 5 engaging the rifiing of the gun barrel, rotates the carrier 5 and likewise imparts rotation to the projectile body 1 2 due to the engagement of the splines 3 thereon with the keyways' 8 in the orifice l of the carrier 5 as heretofore described for the initial form and the modified form of the invention. The magnesium lock pin l5 securing the projectile body "-2 to its carrier 5 due to its direct contact with the powder charge behind the base of the carrier 5 is chemically converted into a gaseous compound by the application of the heat generated upon explosive discharge of the gun's powder charge, releasing the mechanical attachment of the projectile body I -2 to its carrier 5 thereby, permitting separation of the projectile bodyfrom its carrier upon origination of the aerodynamic forces eflfecting the separation thereof, as heretofore described in the initial form of the invention illustrated in Figures 1, 2, 3, and 4. It may 1 be seen that a material other than magnesium may be employed to form the lock pin I 5, for example various forms of fusible alloys having the properties of liquefying upon application of sufiicient heat, such as Newton's alloy, or other well known fusible alloys, but it is believed that a lock pin composed of the metal magnesium is preferable to any fusible means, as its chemical conversion into a gaseous state upon application of sufllcient heat effects a more complete elimination from the gun barrel, of any residue remaining thereof, upon the gun's discharge, than any fusible means so employed.

By referring to Figure 9 in the drawing, a comparison may be made of the cylindrical area of a conventional projectile contacting its gun barrel, with the cylindrical areas of the alternate modified form of duplex projectile contacting its gun barrel, in that conventional projectiles of three to four calibers in length, using the fiat base and conoidal shaped nose construction average a cylindrical area contacting the sides of a gun barrel of approximately 65% to 70% of their cylindrical area. In Figure 9 of the drawing it will be seen ,that the distance B and the distance D are the only cylindrical areas of the alternate modified duplex projectile contacting the bore of a gun barrel, the cylindrical areas A, C, and F.due to their diameters diminishing from the waist B prevent frictional contact thereof with the bore of the gun barrel, where thelines R-R. represent the surface of the rlfiing grooves and the lines L-L represent the surface of the rifle lands, indicating the engagement of the rotation band 6 with the rifle lands. The sum of these cylindrical areas 3" and D in contact with the gun barrel average approximately 35% to 40% of the cylindrical area of the alternate modified duplex projectile, although this form of the duplex projectile is approximately four and onehalf calibers in length not including the projecting portion of the tail thereof through the carrier and in comparison with a conventional projectile of four calibers length of the same caliber, the sum of the cylindrical areas B and D contacting the gun barrel are approximately 40% less in area than the contacting cylindrical area of the conventional projectile. This reduction in the contacting cylindrical area of the alternate modified form of the invention likewise efiects a material saving in the frictional resistance 'thereof with its gun barrel upon discharge therefrom, and offers similar advantages, as the initial form and the modified form of the invention heretofore described.

Figure 9 likewise illustrates the assembly of the alternate modified form of the invention, indicating by dotted lines the engagement of the projectile body I with the orifice .1 of the carrier Ii", also showing the engagement of the splines 3 with the keyways 8. The "tail of the body "is shown projecting beyond the rearward face of the carrier and shows the lock pin I! inserted in the aperture M of the body P for securing the attachment thereof. The carrier 5 is provided with the rotation band 6, and the body I is provided with the detonator head -2.

The view in Figure illustrates a rear end view of the carrier 5* showing the projection of the rotation band 6, also showing the rear of the tail portion of the body i penetrating the carrier 5 and having the. dotted lines to .indicate the aperture M, with the lock pin I! inserted therein,- to efiect full engagement of. the projectile body I with its carrier 5.

The view illustrated in Figure 11 shows a cross sectional view of the alternate modified form -of the invention, and is taken on the line SI l-Sil indicated in Figure 12, and illustrates in detail the engagement of the splines 3 on the body I with the splined keyways 8 on the carrier 5', also indicating the projection of the rotation band 6 on the carrier 5 and the powder chamber 4 contained within the projectile body I.

In Figure 12, a longitudinal sectional view taken on the axis of the alternatemodified form of duplex projectile, at right angles to the view illustrated in Figure 9 shows the detonator head 2 threadably secured to the projectile body I with thepowder chamber 4 contained therein, also showing the splines 3 engaging the keyways 8 of the carrier 5. The lock pin I5 is shown in its secured position in the aparture l 4, with its entering end bent rearward to prevent any possible displacement of the look pin thereafter, and illustrates the wedging action thereof, to the tapered rearward wall of the aperture I4 and the base or rearward face of the carrier 5".

It will be understood howeventhat the alternate modified form of the invention heretofore described and illustrated, may be provided with the conventional cartridge case, having contained therein the required powder charge for discharging the projectile, the said cartridge case to be inserted on the carrier 5" directly behind the rotation band 6 thereon, providing a complete self-contained charge for a rifled gun thereby.

Likewise a duplex projectile cartridge may be provided for conventional small arms, such as rifles, machine guns, etc, by substituting in place of the body portion l with its detonator head 2 thereon, a solid body portion of identical shape thereto, and similarly secured to an identical projectile carrier by similar means, and inserted into the usual conventional cartridge case commonly used for small arms, containing its usual powder charge therein, providing a complete self-conigained charge for conventional small arms there- By referring to the drawing it will be seen that the ratio of the duplex projectile body length to its body diameter is approximately 4.75 to 1, hereinafter referred to as the fineness ratio. An ideal aerodynamic form requires a fineness ratio" of approximately 5.0 to 1, and preferably 6.0

to 1, but due to the extreme length of a duplex I projectile body of this ratio it is deemed impractical to exceed a "fineness ratio" of 5.0 to 1, and it is possible to reduce this fineness ratio" to as little as 3.5 to 1 without seriously impairing the aerodynamic eificiency of this type of projectile.

An advantage to be considered in duplex projectiles in comparison with the conventional projectile is the total bearing length, or distance between the foremost point of contact and the rearmost point of contact of the projectile with its gun bore. In conventional projectiles this total bearing length is never over 75% of the projectiles length, and is usually materially less, approximating in the usual conventional projectile of four calibers length, a bearing length of three calibers. In comparing this with the duplex projectile illustrated in Figures 1, 2, 3, and 4, and the modified form illustrated in Figures 5, 6, '7, and 8 having a total length of five calibers, it can be seen that the total length contacting the gun bore is approximately 80% of the projectile length, or four calibers in length, showing an increase in bearing length of one caliber or 33%% over that of the conventional projectile, and in comparison with the alternate modified form of duplex projectile illustrated in Figures 9, 10, 11, and 12, we find a bearing length of three and three-eighths calibers for this form of duplex projectile having a length of four and three-quarters calibers, or approximately 70% of its length against the conventional projectile bearing length of three calibers, effecting an increase in bearing length of approximately 12V2% for this type duplex projectile over that of the conventional projectile of four calibers length. It is obvious that this increase in bearing length substantially increases the accuracy of gun fire of duplex projectiles over conventional projectiles by reducing the tendency of such projectiles to vacillate along their gun barrels upon discharge therefrom, es-

peciall-y when such gun barrels have become worn by their continual use.

It will be understood that any of the various formsof duplex projectiles illustrated and herein described, may be provided with additional rotation b'ands similar in their application to rotation band 6, positioned about the "waist? B of the projectile bodies I, I or 1 and about the'projectile carriers 5, 5 or 5 as may be required for the particular type of ordnance requiring projectiles provided with a plurality of rotation bands.

Although the forms of the invention illustrated in the drawing and heretofore described applies to'the common, or explosive type projectile, it will be understood that the invention equally applies to various other classes of projectiles, such as armor-piercing projectiles, shrapnel, deck-piercing projectiles, etc.

It is obvious to. those skilled in the art that the splines 3 may be disposed on the carriers 5, 5 and 5 and the recessed keyways 8 may be disposed on the bodies I, I and I respectively in substantially reversed order to that illustrated in the drawing without deviating from the invention as substantially disclosed in this application.

' Likewise, it is obvious that the splines 3'illustrated as being integral with one of the elements may comprise instead, separate splines afilxed to this element in a suitable manner and secure substantially the same results as the integral splines illustrated in the drawing, without departing from the scope of the invention.

As there are numerous variations and modifications of the invention described, it is understood that the description given, is of the preferred forms of the invention. I therefore, do not wish to be limited to the construction set forth,

but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

What is claimed is:

1. A duplex projectile for use in rifled guns comprising a body member of substantially stream-line form together with a detachable base member rearwardly disposed thereon; splined means engaging said members in fixed rotative relation comprising feather keys longitudinally disposed on one of said members engaging slots provided on the other member, and locking means for'securing said members in fixed longitudinal relation comprising key meansengaging a key- Way provided on one of said members and securing the other member thereto, whereby discharge of said projectile causes the disengagement of saidlocking means and permits separation of sai'd'body and base members thereby.

2. A duplex projectile for use in rifled guns comprising a body'of substantially streamlined form including a'detachable base rearwardly disosed thereon; splined means engaging said body and base in fixed rotative relation; and centrifugally actuated resilient means in said base engaging slot means on said body for 'securing'said bodyand base in assembled relation.

3. A duplex projectile for use in rifled guns comprising a body of substantially stream-lined form with a detachable base carrying a rotation band rearwardly disposed thereon; 7 means to engage said body and base in fixed rotative relation; and centrifugally actuated key means in said base engaging a keyway encircling said body for securi'ngsaid base thereto.

j 4. A projectile of aerodynamic form for use in rifled guns comprising a conoidal shaped nose portion, a cylindrical shaped waist portion and a conoidal shaped tail portion including projecting splines positioned thereon and a bevelled groove circumferentially incised therein; a' detachable base carrying a rotation band with its forward end bevelled and containing a conoidal cavity includin'g's'plined keyways therein, for efiecting frictional engagement longitudinally relative to said body, but securing against rotation relative thereto; means recessed within said base and adapted to engage said body groove for securing said body thereto, the said means actuated by the centrifugal force imparted by the rifling for releasing said securement to permit separation of said body and base.

5. A projectile of aerodynamic form comprising aconoidal shapednose portion of one caliber length, a cylindrical shaped waist portion of threequarters caliber length, a conoidal shaped tail por-- tion of three calibers length with projecting splines positioned thereon and a bevelled groove circumferentially incised therein; a carrier forming a cylindricalbase of one and one-half calibers length with its forward end bevelled and containing a conoidal cavity with splined keyways therein, for effecting frictional engagement longitudinally relative to said body but securing against rotation relative thereto, and means recessed within said base and adapted to engage with said body groove, for securing said body thereby, the said means effective upon rotative discharge thereof for releasing said securement thereby I 6. A projectile of aerodynamic form comprising a conoidal shaped nose portion of one caliber length, a cylindrical shaped waist portion of three-quarters caliber length, a conoidal shaped tail portion of three calibers length with projecting splines positioned thereon and a bevelled groove circumferentially incised therein; a carrier forming a cylindrical base of one and onehalf calibers length with its forward end bevelled and containing a-conoidal cavity with splined keyways therein, for effecting frictional engagement longitudinally relative to said body but securing against rotation relative thereto, and internally contracting lock arms recessed within said base, to engage said body groove for securing said body thereby, the said arms centrifugally actuated to release said securement thereby.

'7. A duplex projectile comprising a body of substantially stream-line form including a detachable base rearwardly disposed thereon, means to engage said body and base in fixed relation togeth'er'with fusible means for securing the same.

8. A duplex projectile comprising a body of double conoidal form; a detachable base rearwardly positioned thereon and effecting engagement therewith; means to secure the base against rotation relative to the body; and fusible means securing the body to the base, efiective thermically for releasing said securement thereto.

9. A projectile of aerodynamic form comprising a conoidal shaped nose portion, a cylindrical shaped waist portion, and a conoidal shaped tail portion including projecting splines positioned thereon and a transverse aperture arranged rearwardly therein; a carrier forming a cylindrical base with its toward end bevelled and containing aconoidal orifice including splined keyways therein, for eifecting frictional engagement longitudinally relative to said body but securing against rotation relative thereto; and fusible means bendable afterinsertion in said body aperture and adapted to wedge jagainst the rearward end of said base, for securing said'body thereto, the 1 10 a'conoidal orifice including splined keyways therein, for effecting frictional engagement longitudinally relative to said body but securing against rotation relative thereto, and a magnesium lock pin bendable after insertion in said body aperture and adapted to wedge against the rearward end of said base, for securing said body thereto,

said lock pin efiective thermically for releasing said securement thereby.

KENNETH L. HAYDEN. l0 

